Toxocara spp. seronegativity in Czech patients with early form of multiple sclerosis clinically isolated syndrome

Background: Helminth infections were reported to slightly modulate the host immune system response and decrease the risk of an autoimmune disorder, but on the other hand any infection may activate the immune system and trigger autoimmune reaction. In this study, we aimed to measure eosinoohil levels and antibodies against Toxocara spp. in patients with clinically isolated syndrome (CIS) and multiple sclerosis (MS). Methods: In total. 220 CIS patients and 62 MS patients were examined. Antibodies against Toxocara secretory/excretory antigens (TES) were measured with an ELISA method. Results: A total of 1,983 measurements of eosinophil levels were performed in CIS patients, out of which 95 results in 21 different patients were above the upper normal limit of the laboratory, but it was mostly only a relative increase. Two patients showed eosinophil levels above 20 but both of them suffered from severe allergy. None of the CIS patients had any clinical signs of parasitic infections and the serological tests for antibodies against Toxocara were all negative. In all MS patients, eosinoohil levels were in normal range. Antibodies against TES were detected in only 1 out of 62 (1.6%) MS patients. Conclusions: Based on our results it does not seem that Toxocara infection reoresents a potential trigger of MS. Nevertheless, our study indirectly confirms the hypothesis that parasitic infection may protect from autoimmunity.